Drag Penalty of External Stores

Hallo everybody.
I’m looking for information about the additional drag produced by external stores. Purpose is to make a proper simulation of climb performance. I have zero-lift values for some aircraft and a usable transonic drag model. But I would like to know how many drag-counts are added by external stores like missiles, bombs, whatever.

As not everybody may be familiar with drag counts I’ll be happy with all information you got. For example max speed with a particular load (with information about thrust and altitude). As I have only data for American types I could use information on them best. But any indication about the drag penalty of external stores is welcome.

Thanks
Schorsch